This invention relates to gaskets and heat shields in high temperature fluid handling systems.
In automobile exhaust systems, a series of pipes are interconnected to conduct the flow of hot exhaust gases from the engine to the tailpipe of the automobile. The pipes consist of a manifold pipe and a pipe leading from the exhaust manifold, which are interconnected with flanged members. This portion of the exhaust system transmits the exhaust gas directly from the engine to a pipe or passage leading to the catalytic converter. The flanged connection between these pipes radiates a large amount of thermal energy, which can be detrimental to some of the more sensitive components that are positioned near this joint. These components might include electrical wires and pipes carrying fluid for the engine.
The flanged joint is insulated from the surrounding environment by a heat shield that is attached directly to one or both of the flange members and is separate from the gasket member, which is compressed between these flange members. The gasket member, of course, prevents the direct leakage of exhaust fumes as the exhaust gases pass through the pipes and the shield protects the surrounding environment. The shield requires extensive machining through the flanges so that the shield might be attached thereto. This heat shield also requires additional work by the assembler to place the shield in the proper location, and if not securely fastened can result in a rattle or other disturbing noise within the engine compartment.
It is an object of the present invention to provide an improved gasket and heat shield for a flanged joint connection in a hot gas transmission system.
In one aspect of the present invention, the gasket and heat shield are formed as a unit, which is attached within the flanged joint by conventional flange joint interconnecting fasteners.
In another aspect of the present invention, the gasket portion of the gasket and heat shield is a compressible member, which is compressed between the flanged joints during assembly.
In yet another aspect of the present invention, the heat shield portion of the gasket and heat shield surrounds or encloses the gasket portion and has a first body portion which is sandwiched between the flanged members and a second body portion which is angularly disposed relative to the first body portion, and is positioned between the flanged joints and the surrounding environment.
The gasket and heat shield of the present invention comprise a unitary structure, which is placed between the connecting flanges during initial assembly of the exhaust system. In prior art applications, the gasket member is positioned between the flanges during assembly and the heat shield was added later. With the present invention, the same fasteners, which connect the flanges to form the joint and compress the gasket also maintains the heat shield in the proper location. Since great care is taken in ensuring that the exhaust system is tight, the heat shield will also be connected in a manner that is rigid and not susceptible to rattles.
The gasket and heat shield of the present invention are assembled to the exhaust system with the same fasteners as are currently used as mentioned above. This saves the cost of additional fasteners to attach the heat shield, the cost of additional machining that must be done to support the fasteners of the prior art heat shields, and also ensures that the heat shield is firmly connected into the exhaust system to eliminate rattles. Thus, it is apparent that the present invention provides many advantages over the prior art applications of a separate gasket and heat shield system.